C81.70
BillableOther Hodgkin lymphoma, unspecified site
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C81.70 an HCC code?
Yes. C81.70 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Lymphoma and Other Cancers under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for C81.70
For C81.70 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed C81.70 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C81.70 is the ICD-10-CM diagnosis code for other hodgkin lymphoma, unspecified site. This code represents Hodgkin lymphoma (a type of blood cancer affecting lymph nodes) that doesn't fit into other specific subtypes and hasn't been identified in a particular location in the body. It's used when the exact site of the cancer is unknown or not documented. C81.70 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lymphoid, hematopoietic and related tissue (c81-c96).
Under the CMS-HCC V28 risk adjustment model, C81.70 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors (HCC 21) with a community, non-dual, aged base RAF weight of 0.545. Under the older CMS-HCC V24 model, C81.70 maps to Lymphoma and Other Cancers (HCC 10) with a community, non-dual, aged base RAF weight of 0.675. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Verify documentation for specific lymphoma subtype and anatomical site before defaulting to 'unspecified' - more specific codes provide better clinical detail and may affect treatment planning. Because C81.70 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for C81.70 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify documentation for specific lymphoma subtype and anatomical site before defaulting to 'unspecified' - more specific codes provide better clinical detail and may affect treatment planning
- •If a site is documented, use the appropriate site-specific code (C81.71-C81.79) rather than the unspecified code, as payers may request clarification on unspecified diagnoses
Clinical Significance
Other Hodgkin lymphoma of unspecified site is used when the pathology confirms a Hodgkin lymphoma subtype that does not fit into the standard categories (nodular sclerosis, mixed cellularity, lymphocyte-rich, lymphocyte depleted) and the anatomic site is not documented. This may include rare morphologic variants. The code lacks both subtype and site specificity, which limits clinical utility but still captures the HCC for risk adjustment.
Documentation Requirements
- ✓Pathology confirming Hodgkin lymphoma that does not match standard subtypes
- ✓Documentation explaining why standard subtype classification was not possible
- ✓Query for anatomic site information to use a more specific code when available
- ✓Staging and treatment documentation
- ✓Encounter-specific provider assessment